This article provides results of combined modality treatment of patients with stage IIIA(N2) non-small cells lung cancer with systematic and selective lymph node dissection. Elicit that the selective lymph node dissection is valid for patients with stage IIIA(N2) squamous cell carcinoma and right-sided lung cancer when we provide combined modality treatment using adjuvant radiation therapy. Carrying out that the systematic lymph node dissection is extend disease-free survival and five-year survival rate when we provide combined modality treatment for patients with stage IIIA(N2) squamous cell carcinoma and left-sided lung cancer
